The present invention relates to valves. More particularly, this disclosure provides a magnetically-actuated fluid control valve.
Applications of valves in high-performance fluidics control often require quick response time, small size, long life, and operation under a wide range of fluid flows; often, valves meeting these criteria are required to provide hundred micron throws with several grams of force while closed.
Magnetically-actuated valves are one class of valves which can satisfy these criteria, and an example of such a valve is provided by U.S. Pat. No. 5,085,402. While these magnetically-actuated valves are useful for their intended purposes, one limiting factor in their application is their generally high cost. This high cost may unacceptably drive up cost of a final product, especially in the case of consumer products, where price can critically govern sales.
There are other classes of valves which potentially can provide throws having sufficient force (e.g., piezoelectric valves), but these valves generally are too large and expensive when constructed to meet the criteria mentioned above. Furthermore, piezoelectric valves often require a large driving voltage, which can unacceptably increase power supply requirements.
A need exists for a magnetically-actuated valve that is relatively inexpensive to produce. Ideally, such a valve should be extremely reliable, providing millions of cycles of repetition during the valve""s lifetime. Such a valve should provide strong throws with response time on the order of milliseconds or better. Finally, such a valve should ideally be small. The present invention satisfies these needs and provides further, related advantages.
The present invention solves the aforementioned needs by providing a low-cost, high-performance valve. A valve made according to the present invention utilizes a polarized, magnetic actuator, preferably using a commercial electric relay. Because of today""s market demands, these relays are today both mass-produced and relatively inexpensive. Use of a properly sized relay and other valve components enables fabrication of a valve having zero leak rate, small form factor, and very long lifetime. It is expected that such a valve can be manufactured for a small fraction of the cost of the magnetically-actuated and piezoelectric valves mentioned above, and so, a valve according to the present invention should have ready applicability to consumer markets which have previously not been amenable to the use of high-performance valves.
One form of the invention provides a valve that uses a polarized, magnetic actuator to open and close a valve head against a valve seat. In one detailed aspect of the invention, this actuator uses a pivoting armature which is operatively connected to the valve head, causing it to seal against the valve seat or open as the actuator is driven. Preferably, the actuator can be an electric relay that uses a pivoting xe2x80x9csee-sawxe2x80x9d armature, and a compliant diaphragm; use of either side of the armature to displace the compliant diaphragm enables opening and closing of the valve without significantly changing fluid volume within the valve. In this manner, the actuator can be configured such that the force imposed by the fluid balances in both pivotal directions of the armature, such that there are no significant fluid pressures which act against opening or closing of the valve.
In another form of the invention, the valve uses a magnetic actuator having a pivoting armature to open and close a valve head against a valve seat.
The invention may be better understood by referring to the following detailed description, which should be read in conjunction with the accompanying drawings. The detailed description of a particular preferred embodiment, set out below to enable one to build and use one particular implementation of the invention, is not intended to limit the enumerated claims, but to serve as a particular example thereof.